Study of the protection algorithms in distributed generation systems

Abstract

Current trends in the development of power supply systems for industrial facilities when applying the principles of distributed generation consist in the implementation of power supply from several power sources of different types and characteristics (photovoltaic cells, wind power plants, microturbine plants, diesel power plants), the maximum approximation of power sources to electrical loads, the use of electricity storage. The availability of such installations near consumers reduces the quantitative energy consumption by reducing the technical losses of the ge¬nerated energy and reducing dependence on fossil fuels. However, with these advantages, distri¬buted generation has created technical problems, one of which is the complication of relay protection systems due to the possibility of powering the damage point from different sides. This circumstance requires the development of new algorithms and protection schemes to ensure selectivity and to increase the sensitivity of relay protection. The purpose of the study is to analyze the algorithms of remote protection in distributed generation systems. The methods used comprise an integrated approach, including scientific analysis, processing and analysis of the results of theoretical and experimental studies in the field of relay protection of electrical complexes in networks with distributed generation. The results obtained present the analysis of various algorithms for the implementation of protection, which were implemented as proposals for distribution networks. The system of remote protection in networks containing distributed generation systems is presented, and the algorithms of operation are compared to increase the sensitivity of remote protection devices to the occurrence of various emergency modes: single-phase and three-phase short circuits. Several algorithms for increasing the sensitivity of remote protection for distribution networks in the presence of several power sources are considered. The comparison of these algorithms according to the criteria of the implementation cost, the accuracy of implementation, the number of necessary input data is also carried out. Practical significance of the research the research results can be used to take into account the effect of changes in the parameters of protected connections under conditions of electrical complexes operation in a network with distributed ge¬neration on the effectiveness of remote protection. They make it possible to increase the sensitivity and selectivity of the remote protection operation in case of emergency situations.